1. Technical Field
The present disclosure relates to a refrigeration cycle apparatus.
2. Description of the Related Art
A refrigeration cycle apparatus with multiple compressors arranged in series is known. For instance, as shown in FIG. 5, Japanese Unexamined Patent Application Publication No. 2008-122012 describes an evaporative refrigeration apparatus 300 having a centrifugal compressor 315 and a Roots compressor 316 disposed in series. The centrifugal compressor 315 is located in an upstream stage and the Roots compressor 316 is located in a downstream stage.
The evaporative refrigeration apparatus 300 also includes an evaporator 301, a circulating pump 302, a conduit 303, a load 304, a conduit 305, a condenser 306, a vapor duct 307, and a vapor cooler 317. The evaporator 301 brings evaporative liquid such as water to a boil to make it evaporate under a reduced pressure lower than the atmospheric pressure. Water at a reduced temperature due to boiling and evaporation in the evaporator 301 is then pumped out by the circulating pump 302 and delivered to the load 304 through the conduit 303 to be used for air conditioning. Vapor in saturation generated in the evaporator 301 is first sucked into the centrifugal compressor 315 and compressed in it. The vapor compressed in the centrifugal compressor 315 is then sucked into and compressed by the Roots compressor 316, after which it is directed to the condenser 306.
The vapor cooler 317 is located at a position between the centrifugal compressor 315 and the Roots compressor 316 on the vapor duct 307. The vapor cooler 317 cools the vapor compressed by the centrifugal compressor 315 from superheated vapor state to saturated vapor state or cools the vapor close to saturated vapor state. Such cooling is done by directly spraying water into the vapor or by causing indirect heat exchange between the vapor and atmospheric air or cooling water.